Historically, fertilizing field crops has involved distributing livestock waste, particularly in solid form, onto the surface of soil by a manure spreader using a flail to fling the material to the rear. A more modern side-discharge spreader also deposits solid livestock waste on the surface of the soil.
The advent of confinement systems for animals which include pits below the confinement area produces a large amount of animal waste in a slurry form. This slurry must be handled and disposed of in an environmentally acceptable manner. Typically, the slurry is pumped into a large tank carried by a wagon or mounted on a truck.
One use of this slurry is to spread it or spray it onto the surface of the soil. While this process delivers to the soil advantageous nutrients, it has, as a principle objection, a strong odor which remains after the waste is spread. In addition, spraying slurry onto growing crops presents the problem of coating vegetation with slurry, which can be harmful to growing plants. Moreover, surface spreading of animal waste can be problematic in terms of potential runoff of nitrates and phosphorus into rivers and streams. This is objectionable because livestock waste is high in nitrogen, and swine waste is also high in phosphorus.
To avoid these problems, various methods have been proposed for depositing animal waste slurry underground near growing crops. One method uses a fertilizer knife, such as that illustrated in U.S. Pat. No. 4,592,294 to Dietrich et al. The slurry is delivered behind the knife. However, this leaves a very narrow band of fertilizer having a high concentration of nitrogen and other nutrients.
Another method of subsoil delivery of animal waste employs a standard chisel plow shank with an attached wide cultivator sweep in an attempt to distribute the slurry further laterally and to avoid the limitations associated with a narrow concentration of nutrients. This method, however, presents the problem of a trailing slurry hose that can damage growing crops. The damage caused by the trailing hose, dispensed from the reel carrier, especially when a turn is made, makes it impractical for use at key stages of nutrient consumption in growing crop plants.
Veenhuis B. V. of Raalte (The Netherlands) makes and distributes a full line of slurry dispensing systems, including a slurry reel system. This system utilizes a trailing hose slurry injector. An advantage to a trailing hose injector is its ability to smoothly apply slurry in or onto the soil. The slurry is supplied through the hose, rather than dragged across the land. However, the limitations of this system include a slurry injector that is low to the ground, which provides only limited clearance to growing plants, especially taller plants such as maize. Thus, it is not possible to distribute nutrients to a growing crop once it has reached a certain height using these systems. In addition, the systems require the transport of a large tank (containing the slurry) over the soil causing severe soil compaction.
The present invention is directed to overcoming these and other limitations in the art by providing an apparatus and system for delivering water and nutrients to growing crops without causing structural damage to growing plants and by reducing soil compaction.